How to Pull Environment Variable with InfoPath

Need to pull a user environment variable from the system the form is opened on, specifically username and use it as a value for a field.
It's a stand alone form opened with InfoPath on the local machine, no SharePoint or other solutions involved.

So far all my searches have come up empty.
I'm thinking I may need to add some VB code?

I know InfoPath has a username function however I need to stop using domain level authentication on the form.
And from what I've discovered that only works with domain level authentication